Radiotherapy, also called radiation therapy, uses invisible beams of radiation to kill cancer cells. Radiation damages the genetic material inside cancer cells leading to cell death. The National Cancer Institute (NCI) reports approximately 60 percent of people with cancer undergo radiotherapy as part of their treatment. Although the radiation is directed toward the cancer, surrounding tissues often sustain some injury as well. The side effects of radiotherapy relate to this collateral damage of normal tissues in and around the targeted radiation field. The side effects associated with radiotherapy depend largely on the part of the body receiving treatment.
Fatigue
According to NCI, fatigue is a frequent side effect of most radiotherapy treatments. Many factors influence the risk for and severity of fatigue, including medications, anemia, infection, depression and pretreatment health status. The immune system may also contribute to radiation-related fatigue. Notably, the American Cancer Society (ACS) advises fatigue may last for many weeks to months after radiotherapy ends.
Skin Irritation
Because skin is an actively dividing tissue, it is vulnerable to the effects of radiation. While receiving radiotherapy, people commonly experience skin problems in the area undergoing treatment. NCI explains that redness, blisters, ulcers, sores, dryness, itching and peeling of the skin are possible side effects of radiotherapy. Skin problems associated with radiotherapy are usually temporary. Once treatments are completed, the skin typically heals itself.
Diarrhea
NCI advises radiation therapy to the abdomen, pelvis or stomach often causes diarrhea. The cells that line the intestines are in a constant state of renewal. Active tissues such as those of the intestines are susceptible to radiation injury, which leads to diarrhea. ACS notes diarrhea commonly occurs a few weeks after radiotherapy begins. This side effect typically clears within a few weeks after the last radiotherapy treatment.
Nausea and Vomiting
Radiotherapy to the brain, stomach or intestines may cause nausea and vomiting. NCI notes the risk for these side effects increases in conjunction with the total radiation dose. Taking chemotherapy while on radiotherapy also increases the risk for nausea and vomiting. These side effects typically occur within a few hours of treatment. Doctors can prescribe medications to help control nausea and vomiting side effects of radiotherapy.
Mouth and Throat Problems
NCI explains radiotherapy to the head and neck often causes side effects in the mouth including mouth sores, dry mouth, taste changes, tongue soreness and infections of the gums and teeth. As with the intestines, the tissues of the mouth are vulnerable to the effects of radiation. Mouth sores typically heal shortly after completion of radiotherapy. However, NCI points out that taste changes and dry mouth may persist long term.
References
- National Cancer Institute: Radiation Therapy Questions and Answers
- American Cancer Society: Questions about Radiation Therapy
- National Cancer Institute: Radiation Therapy Side Effects
- American Cancer Society: Possible Side Effects of Radiation Therapy
- National Cancer Institute: Radiation Therapy Side Effects, Fatigue
